Hydrodynamic (fluid film) journal bearings of engines and motors are designed to provide uniform hydrodynamic load-bearing capacity around the circumference of the journal bearing. More particularly, to provide such uniform hydrodynamic load-bearing capacity, the fluid wetted, load-bearing surface area of the journal bearing is designed to be constant around the circumference of the journal bearing.
Loads applied to journal bearings by a journal may often vary around a circumference of the journal bearing, such as the loads provided by the cyclic operation of an internal combustion engine. As a result, a journal bearing which provides uniform hydrodynamic load-bearing capacity around its circumference may be understood to be designed to accommodate the greatest (maximum) load to be experienced by the bearing during rotation of the journal, i.e. a worst case scenario.
As such, in providing a uniform hydrodynamic load-bearing capacity around the circumference of the journal bearing, the journal bearing may be understood to be overdesigned at those locations which are not exposed to the greatest applied loads of the journal. As a result, in those areas of such overdesign, the journal bearing is not optimized with regards to drag and resulting fuel efficiency of the engine.
The present disclosure provides journal bearings and methods of use thereof wherein the journal bearings are designed with a hydrodynamic load-bearing capacity which varies in accordance with the journal loads applied to journal bearing such that energy (power) and fuel economy losses due to drag may be decreased.